The goals of the x-ray crystallography facility are: (i) to enable and facilitate the research of MSKCC laboratories that use x-ray crystallography as a tool to address questions in their research programs, and (ii) to provide structural biology and modeling expertise and guidance to non-structural MSKCC laboratories that benefit from the use of available structures in the design and interpretation of experiments. The facility provides, maintains and upgrades the in-house equipment for data collection, including three Rigaku RU200HB rotating anode x-ray generators, two using focusing mirrors, and one RAXIS-IIC and two RAXIS-IV image-plate detectors, all equipped with cryo-devices. For data processing, the facility provides and maintains both centralized and distributive computational resources; crystallographic and visualization software packages are maintained on centralized servers, and are upgraded to new versions as they become available. The x-ray facility manager has expertise in the use of the majority of the packages, and has the duty of training new users in the use of the crystallographic hardware and software, and assists and troubleshoots when needed. The facility has also set up two collaborations with other institutions in the technological research and development of beamlines at synchrotron facilities. The X9A bending magnet beamline at the Brookhaven National Laboratory was jointly established by MSKCC, Albert Einstein College of Medicine, and Rockefeller University, specifically for the application of the MAD method. It employs a full-time beamline scientist responsible for operating the beamline, training and assisting the users. In addition, the facility is part of the Northeastern Collaborative Access Team that has started developing undulator beamlines at the Advanced Photon Source. To enable members of the broader MSKCC scientific community to use x-ray crystallography and other aspects of structural biology in their research, the facility serves as a centralized resource for crystallization expertise and reagents, and for the retrieval and analysis of structures.